Basics of Cryptography

In this post, we will primarily look into basics of cryptography. First, will look into basic terminologies used in the world of cryptography.

Plaintext

This is the original message or original data that needs to be encrypted. In simple terms, An original message that needs to be encrypted is known as plaintext.

Ciphertext

This is the encrypted message or output message which is produced as output. It mainly depends on plaintext and secret key. For a given plaintext, different secret keys will provide two different ciphertexts. The ciphertext is unintelligible and human can’t understand the ciphertext.

Secret Key

There are two different inputs to encryption algorithm one is plaintext and another one is the secret key. The secret key is a value which is independent of plaintext and the algorithm used.

Encryption Algorithm:

It is an algorithm which transforms and substitutes the plaintext into Ciphertext. There are different algorithm available for the same plaintext and the secret key different algorithm will provide different ciphertext.

Decryption Algorithm:

It is again an algorithm which is reverse of the encryption algorithm. It takes secret key and Ciphertext as input and will provide Plain text as output. Secret key should be same as what we have used for encryption.

Encryption:

The process of converting from plaintext to ciphertext is called as encryption or enciphering.

Decryption:

The process of converting from ciphertext to plaintext is called as decryption or deciphering.

Cryptanalysis:

Cryptanalysis is a technique which used to decipher a ciphertext without the knowledge of encryption details. It is also known as “Breaking the code”.

Cryptography:

The area of study of encryption algorithm and its schemes is called as cryptography.